1. Field of Invention
This invention relates to systems and methods for decoding and presenting encoded audio and visual data. More specifically, this invention relates to systems and methods for playing, browsing and interacting with MPEG-4 coded scenes including one or more audio and/or visual objects.
2. Description of Related Art
MPEG-1 and MPEG-2 encoding and decoding standards are frame-based encoding and decoding techniques. That is, in MPEG-1 and MPEG-2, audio-visual data, such as a video recording, is organized into separate frames, where each frame is a complete image. In MPEG-1 and MPEG-2, the human-recognizable objects within each image are not distinguished from each other in encoding and decoding the data defining the image. Thus, while each frame can be treated independently from any other frame, each frame is itself a unitary element of the audio-visual data. FIG. 1 is an exemplary embodiment of an MPEG-2 playback system.
The Virtual Reality Modeling Language, or VRML, is a computer language that is used to create text descriptions defining three-dimensional synthetic images. That is, VRML is used to define the three-dimensional objects that appear in a synthetic, e.g., computer-generated, image, including shapes and sizes of the objects, the appearance of each object, including, material, color, shading and texture, and the location of each objects, including position and orientation. The objects are generally synthetic, e.g., computer-generated, objects. VRML is also used to define the lighting in the synthetic image, including the type and position of one or more light sources.